Re: [Pyobjc-dev] [ pyobjc-Bugs-1146224 ] varadic class methods don't work

[Ronald O. <ron...@ma...>]

On 22-feb-05, at 14:01, SourceForge.net wrote:

> Bugs item #1146224, was opened at 2005-02-22 13:01
> Message generated for change (Tracker Item Submitted) made by Item  
> Submitter
> You can respond by visiting:
> https://sourceforge.net/tracker/? 
> func=detail&atid=114534&aid=1146224&group_id=14534
>
> Category: None
> Group: None
> Status: Open
> Resolution: None
> Priority: 5
> Submitted By: Michael Hudson (mwh)
> Assigned to: Nobody/Anonymous (nobody)
> Summary: varadic class methods don't work
>
> Initial Comment:
> Try running the following code (also attached):
>
> import traceback
> from Foundation import NSObject
>
> class C(NSObject):
>     def f(self, *args):
>         print self, args
>     def g(cls, *args):
>         print cls, args
>     g = classmethod(g)
>
> try:
>     C.alloc().init().f(1,2,3)
> except:
>     traceback.print_exc()
> else:
>     print "instance method OK"
>
> try:
>     C.g(1,2,3)
> except:
>     traceback.print_exc()
> else:
>     print "class method OK"
>
> print 'f', type(C.__dict__['f'])
> print 'g', type(C.__dict__['g'])
>
> With current svn I get:
>
> <C: 0x365950> (1, 2, 3)
> instance method OK
> Traceback (most recent call last):
>   File "/Users/mwh/f.py", line 19, in ?
>     C.g(1,2,3)
> TypeError: Need 0 arguments, got 3
> f <type 'objc.python_selector'>
> g <type 'objc.native_selector'>
>
> I suspect it's the python_selector/native_selector thing that's
> causing the problem.  I did try and look through the source to see
> why it's happening but I just got very confused.

My comment for revesion 1510 says:
  Due to the way PyObjC is implemented you cannot use varargs function  
(either
  *args or **kwds) as methods. If you try to you'll get unexpected  
behaviour.

  This patch makes using *args or **kwds on objc-methods illegal. Fixing  
the
  issues would be preferable, but is a lot of work.

The traceback is now:
Traceback (most recent call last):
   File "t.py", line 4, in ?
     class C(NSObject):
TypeError: Using function with *args as an objc-method

That's also not very useful behaviour, but at least you get the error  
message a lot sooner :-)

Ronald